Patent Application
20190134977
Thermal inkjet printheads eject fluid ink drops from nozzles by passing electrical current through resistor elements contained in a firing chamber. Heat from a resistor element creates a rapidly expanding vapor bubble that forces a small ink drop out of a nozzle of the firing chamber. When the resistor element cools, the vapor bubble quickly collapses and draws more fluid ink into the firing chamber in preparation for ejecting another drop through the nozzle. Fluid ink is drawn from a reservoir via a fluid slot that extends through the substrate on which the resistor element and the firing chamber are formed.
Features of the present disclosure are illustrated by way of example and not limited in the following figure(s), in which like numerals indicate like elements, in which:
For simplicity and illustrative purposes, the present disclosure is described by referring mainly to an example thereof. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present disclosure. It will be readily apparent however, that the present disclosure may be practiced without limitation to these specific details. In other instances, some methods and structures have not been described in detail so as not to unnecessarily obscure the present disclosure. As used herein, the terms “a” and “an” are intended to denote at least one of a particular element, the term “includes” means includes but not limited to, the term “including” means including but not limited to, and the term “based on” means based at least in part on.
Additionally, It should be understood that the elements depicted in the accompanying figures may include additional components and that some of the components described in those figures may be removed and/or modified without departing from scopes of the elements disclosed herein. It should also be understood that the elements depicted in the figures may not be drawn to scale and thus, the elements may have different sizes and/or configurations other than as shown in the figures.
Disclosed herein are fluid ejection devices and methods for fabricating the fluid ejection devices. The fluid ejection devices, which may also be termed printheads, may be provided on a printhead assembly and may be implemented to deliver droplets of fluid, e.g., ink, onto a media. As discussed herein, the fluid ejection devices may include a plurality of firing chambers arranged in a first column and in a second column, in which an actuator is situated in each of the firing chambers. The first column of firing chambers may be physically separated from the second column of firing chambers by a portioning wall. That is, the portioning wall may block direct fluidic paths between the firing chambers in the first column to the firing chambers in the second column. The tops and bottoms of the firing chambers may also prevent direct fluid paths from being formed between the firing chambers.
In one regard, therefore, fluidic paths between the firing chambers in the first column and the firing chambers in the second column may follow a more circuitous path, which may result in fluidic paths having relatively long distances. That is, for instance, the fluidic paths between the firing chambers may be required to go through multiple fluid feed holes as well as a fluid feed slot. In one regard, through implementation of various features in the fluid ejection devices disclosed herein, cross-talk between the firing chambers in the respective columns of firing chambers may be reduced, minimized, or eliminated.
Cross-talk may be defined as occurring when fluid is ejected through a nozzle corresponding to a firing chamber in one column when an actuator in a firing chamber in another column is activated. That is, when cross-talk occurs, fluid may be unintentionally ejected through a nozzle, which may result in visible printing defects. Cross-talk may occur if a fluidic path between the firing chambers is below a threshold level. The threshold level may be based upon the types and sizes of the actuators, may differ for different configurations, and may be determined through testing. The portioning wall disclosed herein may block the direct fluidic paths between the actuators in the first column and the actuators in the second column thus causing the fluidic paths to be larger than the threshold level.
Through implementation of the fluid ejection devices disclosed herein, the distances between the nozzles of the firing chambers in opposing columns of firing chambers may be relatively smaller than may be possible in fluid ejection devices in which cross-talk may be an issue. That is, for instance, the portioning wall disclosed herein may enable for the nozzles of the firing chambers in opposing columns of firing chambers to be positioned in relatively close proximities to each other, e.g., around 100 microns, without a significant risk of cross-talk occurring. In one regard, placing the nozzles of the firing chambers in opposing columns in close proximities to each other may result in higher quality printing, e.g., reduced printed line width. Additionally, the closer proximities of the nozzles may enable a higher nozzle packaging density, a cooler fluid ejection device, etc.
With reference first to
The print media 118 may be any type of suitable sheet or roll material, such as paper, card stock, transparencies, Mylar, and the like. The nozzles 116 may be arranged in one or more columns or arrays such that properly sequenced ejection of ink from the nozzles 116 causes characters, symbols, and/or other graphics or images to be printed on print media 118 as the printhead assembly 102 and print media 118 are moved relative to each other. As discussed in greater detail herein, the columns of nozzles may be positioned in close proximity to each other and may be separated by a portioning wall. For instance, the nozzles in one column may be separated from the nozzles in another column by a distance that is less than about 100 microns.
The ink supply assembly 104 may supply fluid ink to the printhead assembly 102 and, in one example, includes a reservoir 120 for storing ink such that ink flows from the reservoir 120 to the printhead assembly 102. The ink supply assembly 104 and the printhead assembly 102 may form a one-way ink delivery system or a recirculating ink delivery system. In one example, the printhead assembly 102 and the ink supply assembly 104 are housed together in an inkjet cartridge or pen. In another example, the ink supply assembly 104 is separate from printhead assembly 102 and supplies ink to the printhead assembly 102 through an interface connection, such as a supply tube. In either example, the reservoir 120 of ink supply assembly 104 may be removed, replaced, and/or refilled. Where the printhead assembly 102 and the ink supply assembly 104 are housed together in an inkjet cartridge, the reservoir 120 may include a local reservoir located within the cartridge as well as a larger reservoir located separately from the cartridge.
The mounting assembly 106 may position the printhead assembly 102 relative to the media transport assembly 108, and the media transport assembly 108 may position the print media 118 relative to the printhead assembly 102. Thus, a print zone 122 may be defined adjacent to the nozzles 116 in an area between the printhead assembly 102 and the print media 118. In one example, the printhead assembly 102 is a scanning type printhead assembly in which the mounting assembly 106 may include a carriage for moving the printhead assembly 102 relative to the media transport assembly 108 to scan across the print media 118. In another example, the printhead assembly 102 is a non-scanning type printhead assembly. In this example, the mounting assembly 106 fixes the printhead assembly 102 at a prescribed position relative to the media transport assembly 108. Thus, the media transport assembly 108 may position the print media 118 relative to the printhead assembly 102.
The electronic controller 110 may include a processor, firmware, software, one or more memory components including volatile and non-volatile memory components, and other printer electronics for communicating with and controlling the printhead assembly 102, the mounting assembly 106, and the media transport assembly 108. The electronic controller 110 may receive data 124 from a host system, such as a computer, and may temporarily store the data 124 in a memory (not shown). The data 124 may be sent to the inkjet printing system 100 along an electronic, infrared, optical, or other information transfer path. The data 124 may represent, for example, a document and/or file to be printed. As such, the data 124 may form a print job for the inkjet printing system 100 and may include one or more print job commands and/or command parameters.
In one example, the electronic controller 110 controls the printhead assembly 102 for ejection of ink drops from the nozzles 116. Thus, the electronic controller 110 may define a pattern of ejected ink drops which form characters, symbols, and/or other graphics or images on the print media 118. The pattern of ejected ink drops may be determined by the print job commands and/or command parameters.
The printhead assembly 102 may include a plurality of fluid ejection devices (printheads) 114. In one example, the printhead assembly 102 is a wide-array or multi-head printhead assembly. In one implementation of a wide-array assembly, the printhead assembly 102 includes a carrier that carries the plurality of fluid ejection devices 114, provides electrical communication between the fluid ejection devices 114 and the electronic controller 110, and provides fluidic communication between the fluid ejection devices 114 and the ink supply assembly 104.
In one example, the inkjet printing system 100 is a drop-on-demand thermal inkjet printing system in which the fluid ejection devices 114 are thermal inkjet (TIJ) printheads. The thermal inkjet printheads may implement thermal resistor ejection elements in an ink chamber to vaporize ink and create bubbles that force ink or other fluid drops out of the nozzles 116. In another example, the inkjet printing system 100 is a drop-on-demand piezoelectric inkjet printing system in which the fluid ejection devices 114 are piezoelectric inkjet (PIJ) printheads that implement piezoelectric material actuators as ejection elements to generate pressure pulses that force ink drops out of the nozzles 116.
Turning now to
With reference now to
The portion of the fluid ejection device 200 depicted in
The fluid ejection device 200 may include a first column 206 of firing chambers 202 and a second column 208 of firing chambers 202. That is, a first group of firing chambers 202 is provided along the first column 206 and a second group of firing chambers 202 is provided along the second column 208. As shown in
The firing chambers 202 are also depicted as including side walls 212 that may physically separate the firing chambers 202 in the first column 206 from each other and the firing chambers 202 in the second column 208 from each other. The side walls 212 may be formed in the membrane 204 during formation of the firing chambers 202. Although not shown in
As also shown in
The fluid ejection device 200 may also include a substrate 230 upon which the membrane 204 may be attached and which may form a ceiling of the firing chambers 202. According to an example, the substrate 230 may be formed of silicon or other material, such as polymer, plastic, or the like. In any regard, a plurality of fluid feed holes 232 may be formed through the substrate 230 such that fluid from a fluid feed slot (not shown) may be supplied into the respective firing chambers 202. That is, each of the firing chambers 202 may include a respective fluid feed hole 232 through which fluid may be supplied into the firing chambers 202. With reference to
As also shown in
Activation of an actuator 220 may cause part of the fluid contained in the firing chamber 202 in which the actuator 220 is provided to be ejected through the nozzle 242 positioned beneath the actuator 220. In addition, activation of the actuator 220 may cause fluid to be drawn into the firing chamber 202 from the fluid feed slot through the fluid feed hole 232 to fill the firing chamber 202 with fluid. As shown in
As discussed herein, cross-talk may be defined as occurring when fluid is ejected through a nozzle 242 corresponding to a firing chamber 202 in one column 206 when an actuator 220 in a firing chamber 202 in another column 208 is activated. That is, when cross-talk occurs, fluid may be unintentionally ejected through a nozzle 242, which may result in printing defects. In addition, cross-talk among firing chambers 202 may occur if a fluidic path between the firing chambers 202 is below a threshold level. The threshold level may be based upon the types and sizes of the actuators 220. Thus, for instance, the threshold level at which cross-talk may occur among the actuators 220 may be determined through testing and may vary for different configurations. The portioning wall 210 may block the direct fluidic paths between the firing chambers 202 in the first column 206 and the firing chambers 202 in the second column 208. Instead, the fluidic paths between these firing chambers 202 may extend through respective fluid feed holes 232 as well as the distance between the fluid feed holes 232 through the fluid feed slot. In one regard, therefore, the portioning wall 210 may enable the actuators 220 in the respective columns 206 and 208 to be positioned in close proximities to each other, e.g., around 100 microns, without substantial risk of cross-talk among the firing chambers 202 in which those actuators 220 are positioned.
According to an example, the substrate 230 may have a thickness, i.e., in the z-dimension, that is at least 100 microns. In this regard, in order for cross-talk to occur between a firing chamber 202 of the first column 206 and a nearest neighbor firing chamber 202 in the second column 206, a pressure wave formed through activation of the actuator 220 in the firing chamber 202 of the first column 206 may need to traverse at least two fluid feed holes 232 and the distance between the two fluid feed holes 232. In an example in which the height of each of two fluid feed holes 232 is 100 microns and distance between the fluid feed holes 232 is 200 microns, the length of the fluidic path between the nearest neighbor firing chambers 202 in the first and second columns 206, 208 may at least be 400 microns. Thus, for instance, the distance between the neighboring firing chambers 202 may be substantially larger than the threshold level at which cross-talk may occur.
With reference now to
The portion of the fluid ejection device 300 depicted in
The fluid ejection device 300 may include a first column 306 of firing chambers 302 and a second column 308 of firing chambers 302. That is, a first group of firing chambers 302 may be provided along the first column 306 and a second group of firing chambers 302 may be provided along the second column 308. As shown in
The firing chambers 302 are also depicted as including side walls 312 that may physically separate the firing chambers 302 in the first column 306 from each other and the firing chambers 302 in the second column 308 from each other. The side walls 312 may be formed in the membrane 304 during formation of the firing chambers 302. The fluid ejection device 300 may also include a top plate 314 that may form ceilings of the firing chambers 302 and may also act as a barrier for fluid from flowing from one firing chamber 302 to another firing chamber 302 over the tops of the side walls 312. The top plate 314 may be formed of the same or similar material as the membrane 304.
As also shown in
In any regard, the actuators 320 may generate pressure pulses that cause some of the fluid contained in the firing chambers 302 to be expelled from the firing chambers 302 through the nozzles 332 in the substrate 330. The substrate 330 may be attached to the membrane 304 opposite the top plate 314 and may form floors of the firing chambers 302. The substrate 330 may be formed of any of the materials discussed above, for instance, silicon.
According to an example, the pressure pulse created by an actuator 320 may cause some of the fluid contained in a firing chamber 302 to be expelled through the nozzle 332. In the arrangement shown in
As shown in
The portioning wall 310 may block the direct fluidic paths between the actuators 320 in the first column 306 and the nozzles 332 in the second column 308 of firing chambers 302. Instead, the fluidic paths between the actuators 320 and the nozzles 332 in opposite columns 306, 308 may extend out of the firing chambers 302 and over the top plate 314. In one regard, therefore, the portioning wall 310 may enable the nozzles 332 in the respective columns 306 and 308 to be positioned in close proximities to each other, e.g., around 100 microns, without substantial risk of cross-talk among the actuators 320 and the nozzles 332 in the opposite columns 306, 308. According to an example, the top plate 314 may have a width, i.e., in the y-dimension, that is at least 200 microns. In this regard, in order for cross talk to occur between an actuator 320 in a firing chamber 302 of the first column 306 and a nozzle 332 in a nearest neighbor firing chamber 302 in the second column 306, a pressure wave formed through activation of the actuator 320 in the firing chamber 302 of the first column 306 may need to traverse at least two 200 microns. Thus, for instance, the distance between the actuators 320 and nozzles 332 in neighboring firing chambers 302 may be substantially larger than the threshold level at which cross-talk may occur.
With reference now to
The description of the method 400 is made with reference to the fluid ejection devices 200 and 300 depicted in
At block 402, a plurality of holes may be formed on a substrate 230, 330. The holes may be formed through etching of the substrate 230, 330. In addition, the holes may be formed as fluid feed holes 232 (fluid ejection device 200) or as nozzles 332 (fluid ejection device 300).
At block 404, a first column 206, 306 of firing chambers 202, 302 and a second column 208, 308 of firing chambers 202, 302 may be formed in a membrane 204, 304. The firing chambers 202, 302 may be formed in the membrane 204, 304 through etching or other suitable semiconductor fabrication process. In forming the firing chambers 202, 302, a plurality of side walls 212, 312 may be formed between adjacent ones of the firing chambers 202, 302 along the first columns 206, 306 and along the second columns 208, 308. In addition, back walls (not shown) may be formed in the membrane 204 along the opposite ends of the side walls 212 from the portioning wall 210. The back walls may not be provided to enable fluid from a fluid feed slot to be delivered into the firing chambers 202 through the rear ends of the firing chambers 202, for instance, in instances in which the fluid feed holes 232 become blocked or clogged.
At block 406, a portioning wall 210, 310 may be formed in the membrane 204, 304 between the first column 206, 306 of firing chambers 202, 302 and the second column 208, 308 of firing chambers 202, 302. As discussed herein, the portioning wall 210, 310 may cause a fluid path between the firing chambers 202, 302 in the first column 206, 306 and the second column 208, 308 to be of sufficient length to reduce or minimize cross-talk.
At block 408, an actuator 220, 320 may be provided in each of the firing chambers 202, 302. The actuators 220, 320 may be provided on the substrate 230, 330.
A nozzle layer 240 containing nozzles 242 may also be provided on the membrane 204, for instance, as shown in
Although described specifically throughout the entirety of the instant disclosure, representative examples of the present disclosure have utility over a wide range of applications, and the above discussion is not intended and should not be construed to be limiting, but is offered as an illustrative discussion of aspects of the disclosure.
What has been described and illustrated herein is an example of the disclosure along with some of its variations. The terms, descriptions and figures used herein are set forth by way of illustration only and are not meant as limitations. Many variations are possible within the spirit and scope of the disclosure, which is intended to be defined by the following claims—and their equivalents—in which all terms are meant in their broadest reasonable sense unless otherwise indicated.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2016/044082 | 7/26/2016 | WO | 00 |
